Slipping standards?

It seems that having a PhD does not go well with politics as events in Germany and Libya seem to attest.  While most criticism is bound to be directed at the individuals concerned, I find myself wondering what the supervisors and examiners were - or rather, weren't - doing in all of this.  Didn't they question the dissertations in front of them?  Didn't they notice the plagirism?  And for the supervisors: did they not see the difference in writing styles between their students and the final product during the course of study?